Space discharge device



July 28, 1936. Q E MlLLER 2,049,167

SPACE DISCHARGE DEVICE Filed Oct. 22, 1954 INVENTQR ATTORNEY PatentedJuly 28, 1936 a STATES GFE'ECE SPACE DISCHARGE DEVICE Carl F. Miller,Emporium, Pa., assignor to Hygrade Sylvania Corporation, Salem, Mass, acorporation of Massachusetts Application October 22, 1934, Serial No.749,344

6 Claims.

closing envelope.

Accordingly one of the principal objects of this invention is to providea novel form of spacer whereby the electrodes of a radio tube, lamp orsimilar device can be maintained in predetermined fixed spatialrelations with respect tothe enclosing envelope and with respect to oneanother.

:It has been proposed heretofore to provide the electrode assembly ormount of a radio tube or the like with a disc or similar member which isadapted to bear against the inner wall of the tube envelope to steadythe electrode assembly. For example, one known type of spacer for thispur pose consists of a disc of mica or similar insulating materialprovided with a series of aligned perforations adapted to register withthe several electrode support posts, said member having edge projectionsto engage the wall of the envelope. This type of spacer has thedisadvantage however that since it is assembled in end-on relation andover the ends of the supporting posts, it is not possible for the personassembling the device to view conveniently the interelectrode spacing,and in the case of tubes having a large number of electrodes eachelectrode support post must be manually and individually aligned withits corresponding perforation in the spacer member. Because of theend-on assembly method necessitated by this prior type of spacer disc,unless the various electrode support posts are held in the proper spacedrelation during the assembly of the spacer, much time is consumed ineffecing the proper assembly of the spacer. Furthermore anynon-uniformity of spacing between the various posts as compared with thedisc perforations, may require a forcing of the disc into position withthe possibility of chipping the edges of one or more of theperforations, thus introducing a source of non-uniformity in thefinished tube.

- Accordingly another object of this invention is to provide a bi-partspacer member which may be assembled in such a way that during theassembly operation the interior spacing of the electrodes may be clearlyobserved.

A feature of the invention relates to a bi-part spacer member which iscapable of being assembled in a motion which is substantiallyperpendicular to the longitudinal axis of the electrode assembly.

Another feature relates to a bi-part spacer member'having cooperatingnotches in opposing edges to define a plurality of perforations forreceiving and spacing the support posts of an electrode assembly.

10 A further feature relates to a spacer member wherein the leakage pathbetween the several electrode posts passing therethrough is materiallyreduced.

A still further feature relates to a spacer member having a plurality ofsubstantially circular perforations adapted to receive electrode supportposts and a rectangular perforation to receive an electron-emittingcathode member.

A still further feature relates to a spacer member which is capable ofbeing assembled so that it is positioned between, and supports the turnsof a helically wound electrode or similar member.

Other features and advantages not specifically enumerated will beapparent after a consideration of the following detailed descriptionsand the appended claims.

While the invention will be described herein as embodied in one knowntype of discharge device, namely, a dome type radio tube, it will beunderstood that this is done merely for purposes of explanation and notby way of limitation.

Accordingly in the drawing, Fig. 1 is a top plan view, partly insection, of a tube embodying features of the invention.

Fig. 2 is a partial sectional view of a tube such as ispartlyillustrated in Fig. 1.

Fig. 3 is an explanatory diagram showing the manner in which the bi-partspacer member is assembled.

Fig. 4 is a detailed sectional view of the arrangement of Fig. 1 alongthe line 4-4 but with certain of the parts omitted for clarity.

Fig. 5 shows an alternative arrangement wherein the spacer memberintersects one of the electrodes between adjacent turns.

Referring more particularly to Figs. 1 and 2, the numeral 1 representsan enclosing envelope such as is ordinarily employed in radio tubes,lamps or similar devices. Preferably, although not necessarily, theenvelope l terminates at its upper end in a portion 2 of reduceddiameter, this portion being provided, if necessary, with a metallicconnection cap 3 of known construction. The envelope I may be providedat its lower end with a mount including an electrode assembly and areentrant stem terminating in a press (not shown) wherein the variouslead-in and electrode support wires are sealed. As shown in Figs. 1 'to3 of the drawing the electrode assembly of the mount may comprise acentral tubular or cylindrical cathode member 4 and a plurality ofconcentric electrodes 5, 8, I, 8. Thus for example, the electrodes 5, 6and I may consist of wire wound, or other foraminous structures capableof acting as grids, while the electrode 8 may consist of a solid orperforated plate adapted to act as' an anode. Each of the electrodes 5,6, I and 8 may be provided with a pair of vertical uprights orsupporting posts. Thus the grid 5' is wound around or is supported bythe posts 9, I the grid 6 is supported by posts I I, I2; grid issupported by posts I3, I4; while the plate 8 is supported by posts I5,I6. Preferably the various electrode supporting posts extend slightlybeyond the ends of the associated electrodes as clearly shown in Fig. 2of the drawing.

For the purpose of spacing the several electrodes from one another thereis provided, in

, accordance with the invention, a bi-part spacer member comprising thepart I! and the part I8. Parts I! and I8 may be made of any suitablematerial preferably an insulating material such as mica or the like. Asshown clearly in Figs. 1

:and 3, the part I! is provided with oppositely extending arms I9, 28and a third arm 2I extending at right angles to arms I9 and 20. Eachofthe said arms is provided with smaller projections or teeth 22 whichare adapted to engage the inner wall of the portion 2 of the envelope asshown clearly in Fig. 1 of the drawing. The arms I9 and 28 are providedwith two circular perforations adapted to register with and fit over theplate support posts I5, I6. The said perforajtions in member I! are inalignment with the edge 23 which in turn is provided with a series ofaligned notches adapted to register with corresponding posts 9 to I4inclusive. The said edge is also provided with a V-shaped notch adaptedto register with the tubular cathode member 4. Preferably the notchesregistering with the support wires 9 to I4 are semi-circular although ifdesired these notches may be V-shaped.

The part I8 of the bi-part spacer member is likewise provided with apair of perforations adapted to register with the posts I and I8 and theedge 24 is also provided with a series of semicircular notches 25, 26,2!, 28, 28, 38, and with a central V-shaped notch 3 I. The notches inmember I8 are so arranged that when the said member is assembled asshown in Fig. 1 the cooperating notches in the edges 23 and 24 define acentral rectangular perforation to receive the cathode member 4 and aplurality of sets of circular perforations to receive the posts 9 to I4.Preferably the V-notches are so designed that when the parts I-!, and I8are assembled they define a square opening having a width substantiallyequal to the diameter of the cathode member 4, so that the said cathodemember is supported at four points around its periphery.

The manner of assembly of the spacer member is believed to be obviousfrom the foregoing description. Suflice it to say that the member I! Vis first placed in position with the outer perforations engaging platesupport posts I5 and I6 and if desired the said member I! may rest uponand be supported by the upper edge of the cylindrical electrode 8 asshown more clearly in Fig. 2. Likewise the member I8 is then assembledover the post I5 as indicated in Fig. 3 and the said member is thenswung around until the notches in the edge 24 engage the associatedelectrode support posts whereupon the tongue 3| may be slipped over thepost I6. With the parts thus 5 assembled, small metal cross pieces 32,33 may be welded to the posts I5, I6 to fasten the spacer membersagainst vertical movement.

As will be noticed from the showing of Fig. 4, the members I! and I8when assembled are not in the same plane so that the effective length ofthe leakage path between the several electrode support .posts iscorrespondingly increased. The electrode assembly having the spacermeans fastened thereto is then positioned within the envelope I, so thatthe teeth 22 flexibly engage the wall portion 2. Consequently theelectrode assembly is thus supported against tilting movement onopposite diameters.

If desired the members I! and I8 in addition to supporting the electrodeassembly against tilting movement with respect to the envelope I mayalso be used to support one or more of the grid electrodes 5, 6 and I.Thus as shown in Fig. 5 the electrode 5 consisting of a wire 34helically wound around the support posts 9 and I0 is slightly longerthan the anode 8 so that when the members I! and I8 are assembled theyintersect the grid electrode between two adjacent turns. hers I! and I8support the grid electrode against tilting movement in the mannerdescribed in con- 1 nection with Figs. 1 to 3 and at the same time thesaid grid is supported against vertical movement by reason of theinterlocking arrangement between the members I! and I8 and theassociated grid turns.

While specific shapes and arrangements of the members I! and I8 havebeen disclosed herein,

it will be understood that the invention is not limited thereto. Forexample, where the antitilting effect is not desired the arms I9, 20 and2| may be omitted in which event the bi-part members I! and I8 servemerely to space the various electrodes from one another. Furthermorewhile one specific manner of engaging the envelope with the spacer isshown, various modifications and changes may be made therein withoutdeparting from the spirit and scope of the invention.

The foregoing arrangements provide means for supportingthe elements of atube so that there is a minimum of microphonic noise or electrical.-disturbance resulting from the tight-fit that is obtained between themica and the various support posts; Furthermore the chances of the ele-iments of the electrode assembly rattling or being mechanically jarredare materially reduced.

What I claim is:

1. An electron discharge device having an envelope, a mount within saidenvelope and comprising a plurality of electrodes having side posts, aninsulating spacer having an edge provided with a plurality of slots,said side posts being received in saidrslots to space said electrodes infixed relation with respect to each other and an insulating membercooperating with said spacer for closing the ends of said slots to locksaid side posts in said slots.

2. An electron discharge device having an envelope,.a mount within saidenvelope and comprising a plurality of electrodes having side posts, aninsulating spacer having an edge provided with slots for receiving theends of said side posts,

a second insulating spacer having an edge pro-.75

By this arrangement therefore, the mem- 30 Y vided with slots inregistry with the slots in said first spacer, said spacers beingpositioned to lock said side posts between said spacers within saidslots.

3. An electron discharge device having an envelope, a mount within saidenvelope comprising a plurality of electrodes having side posts withtheir ends in alignment, a spacer positioned on one side of said sideposts and provided with apertures in which the end side posts arereceived and a straight edge having slots in which the rest of the sideposts are received, a second spacer positioned on the other side of saidside posts above said first spacer and in contact therewith and havingapertures in which the end side posts are received and a straight edgehaving slots in registry with the slots on said first spacer in whichthe rest of the side posts are received, said spacers being secured tosaid end side posts to lock the side posts in the slots between saidspacers.

4. A device of the character described comprising an electrode assemblysaid assembly including a pair of electrodes, and means for spacing saidelectrodes comprising a pair of separable insulator members havingregistering notches in 'their opposed edges said notches engagingcorresponding projections on said electrodes.

5. A device according to claim 4 in which certain of said registeringnotches define a circular opening and others of said notches define arectangular opening.

6. A device of the character described comprising a tubular cathodemember, an electrode having a supporting post, means to space saidcathode from said electrode comprising a bi-part insulator member theopposing edges of each part of said member being provided withregistering notches one set of notches defining a circular opening toreceive said post, and the other set defining a rectangular opening toreceive said cathode member.

CARL F. MILLER.

